UN Secretary-General Kofi Annan called on people ahead of World AIDS Day on Friday to hold their leaders accountable and to keep momentum strong in the fight against AIDS. At a public commemoration ceremony held at St. Bartholomew's Church in New York on Thursday, Annan told the audience that the virus, which has killed 25 million people and infected 40 million more, is "the greatest challenge of our generation," but noted changing attitudes in the last decade. "Financial resources are being committed like never before, people have access to antiretroviral treatment like never before, and several countries are managing to fight the spread like never before," the secretary-general said. "Now, as the number of infections continues unabated, we need to mobilize like never before." Continuing the push against the growing epidemic requires "every president and prime minister, every parliamentarian and politician, to declare that 'AIDS stops with me,"' he said. This year marks the 19th World AIDS Day, the 25th year since the first case of AIDS was identified and 10 years since the formation of UNAIDS, the UN arm formed to fight the virus. Citing this year's World AIDS Day theme of accountability, Annan said politicians should protect vulnerable groups, including sex workers and people living with HIV. He also said they need "to work for real, positive change that will give more power and confidence to women and girls, and transform relations between women and men at all levels of society." Due to erratic condom use and the virus' spread into new populations, like married women, HIV has made a worrying return to countries such as Thailand and Uganda. Annan, who was accompanied his wife Nane at the New York event, noted that accountability to eradicate AIDS is not limited to politicians. Rates of HIV infection continue to grow, with 4 million new cases worldwide every year. The battle is waged even in countries that were previously models of control. The world will miss the UNAIDS 2010 target of treating 9.8 million people with antiretrovirals by more than half, according to the International Treatment Preparedness Coalition. Annual investments in the response to AIDS in low- and middle-income countries now stand at more than US$8 billion (euro6 billion), but Annan speculated in an earlier statement that by 2010 total need will exceed US$20 billion (euro15 billion) annually. Still, he remained resolute about the UN meeting its goals to fight the virus, which including halting and starting to reverse the AIDS epidemic by 2015. "Because the response has started to gain real momentum, the stakes are higher now then than ever before," Annan said. "We cannot risk letting the advances that have been achieved unravel; we must not jeopardize the heroic efforts of so many."